test: add integration test for irqbalance

Add integration tests for the irqbalance CPU ban list
save/restore feature.

Signed-off-by: Francesco Romani <fromani@redhat.com>

test/irqbalance.bats

@@ -0,0 +1,99 @@
+#!/usr/bin/env bats
+# vim: set syntax=sh:
+
+load helpers
+
+function detect_irqbalance_config() {
+	# debian/ubuntu
+	[ -f /etc/default/irqbalance ] && echo "/etc/default/irqbalance"
+	# fedora/centos/RHEL
+	[ -f /etc/sysconfig/irqbalance ] && echo "/etc/sysconfig/irqbalance"
+	# default - we need to have something!
+	echo "/etc/sysconfig/irqbalance"
+}
+
+CONFIGLET="$CRIO_CONFIG_DIR/99-irqbalance.conf"
+IRQBALANCE_CONF=$(detect_irqbalance_config)
+# default setting
+BANNEDCPUS_CONF="/etc/sysconfig/orig_irq_banned_cpus"
+
+function setup() {
+	setup_test
+	start_crio
+	# we don't uncondintionally restore because the irqbalance package may be missing
+	# from the test system. if this is the case, one less thing to worry about, we can't
+	# pollute the system state anyway :)
+	if [ -f "$IRQBALANCE_CONF" ]; then
+		cp -v "$IRQBALANCE_CONF" "$IRQBALANCE_CONF".bkp
+	else
+		# placeholder to make the rest of the suite simpler.
+		# note it's intentionally commented.
+		echo "# IRQBALANCE_BANNED_CPUS=" > "$IRQBALANCE_CONF"
+		touch /tmp/.test_owns_irqbalance_conf
+	fi
+	if [ -f ${BANNEDCPUS_CONF} ]; then
+		cp -v "$BANNEDCPUS_CONF" "$BANNEDCPUS_CONF".bkp
+	else
+		# empty file is fine and meaningful
+		touch "$BANNEDCPUS_CONF"
+		touch /tmp/.test_owns_bannedcpus_conf
+	fi
+}
+
+function teardown() {
+	cleanup_test
+	# see setup about why we have these conditionals
+	if [ -f "$IRQBALANCE_CONF".bkp ]; then
+		mv -v "$IRQBALANCE_CONF".bkp "$IRQBALANCE_CONF"
+	elif [ -f /tmp/.test_owns_irqbalance_conf ]; then
+		rm -f "$IRQBALANCE_CONF"
+		rm -f /tmp/.test_owns_irqbalance_conf
+	# else how come?
+	fi
+	if [ -f "$BANNEDCPUS_CONF".bkp ]; then
+		mv -v "$BANNEDCPUS_CONF".bkp "$BANNEDCPUS_CONF"
+	elif [ -f /tmp/.test_owns_bannedcpus_conf ]; then
+		rm -f "$BANNEDCPUS_CONF"
+		rm -f /tmp/.test_owns_bannedcpus_conf
+	fi
+}
+
+@test "irqbalance cpu ban list save" {
+	# given
+	if ! grep -Eq '^f{1,}$' /proc/irq/default_irq_smp_affinity; then
+		skip "requires default IRQ smp affinity (not banned CPUs)"
+	fi
+	[ -f "$CONFIGLET" ] && rm -f "$CONFIGLET"
+
+	[ -f "$BANNEDCPUS_CONF" ] && rm -f "$BANNEDCPUS_CONF"
+
+	# when
+	restart_crio
+
+	# then
+	len=$(awk 'END {print NR}' "$BANNEDCPUS_CONF")
+	[ "$len" -eq 0 ]
+}
+
+@test "irqbalance cpu ban list restore - default" {
+	# given
+	if ! grep -Eq '^f{1,}$' /proc/irq/default_irq_smp_affinity; then
+		skip "requires default IRQ smp affinity (not banned CPUs)"
+	fi
+	[ -f "$CONFIGLET" ] && rm -f "$CONFIGLET"
+
+	truncate -s 0 "$BANNEDCPUS_CONF"
+
+	# whem
+	restart_crio
+
+	# then
+	len=$(awk 'END {print NR}' "$BANNEDCPUS_CONF")
+	[ "$len" -eq 0 ]
+	banned_cpus=$(sed -n 's/^IRQBALANCE_BANNED_CPUS=\(.*\)/\1/p' "$IRQBALANCE_CONF")
+	[ -z "$banned_cpus" ]
+}
+
+# disable restore file, check it does NOT clear the irqbalance config
+
+# explicit restore file, check it does SET the irqbalance config accordingly